Question: Simplify the following expression: $q = \dfrac{1}{10y} + \dfrac{1}{2y}$
Explanation: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $10y$ and $2y$ $\lcm(10y, 2y) = 10y$ $ q = \dfrac{1}{1} \cdot \dfrac{1}{10y} + \dfrac{5}{5} \cdot \dfrac{1}{2y} $ $q = \dfrac{1}{10y} + \dfrac{5}{10y}$ $q = \dfrac{1 +5}{10y}$ $q = \dfrac{6}{10y}$ Simplify the expression by dividing the numerator and denominator by 2: $q = \dfrac{3}{5y}$